Most paramedics are aware that
in the United States, ED physicians have been using ultrasound
machines for
several years now. Specifically the physicians are doing a Focused Assessment Sonography in Trauma (FAST)
or Enhanced FAST
(E-FAST) exams. For critical medical patients the Rapid Ultrasound in SHock
(RUSH) exam,
or similar exam may be performed.
This is different from calling in a sonographer or sending the patient to the
radiology/ultrasound department for a comprehensive scan. This quick, limited use is known as point-of-care testing
and has been extremely useful in quickly refining the correct diagnosis. When I first read an article in JEMS about Odessa Texas
Paramedics using an ultrasound machine
in an ambulance, I thought to myself this is a crazy idea and it would never
fly.

The reasons I thought this would never catch on:

They are too expensive, the machines must cost
hundreds of thousands
dollars.

Training a paramedic to use the ultrasound
machine might
take hundreds of additional hours.

EMS agencies would not be reimbursed by insurance companies.

The machines are very complicated to run.

The images are too fuzzy, most paramedics will not be able
to read them especially bouncing down the road in a moving ambulance.

All it will tell me is the patient is
pregnant.

Scanning a patient will delay definitive care.

Physicians here will never go for this.

Paramedics are not licensed to use an ultrasound machine. It
requires radiation technology and ultrasound training to be licensed to use
them.

Ultrasound (US) energy is a form of non-ionizing radiation and
could be harmful to patients.

Physical Exam can give me the same
information.

How is this going to change the care we
give?....probably not at all I thought.

Then I did my homework and found that none of these concerns
were valid. I remember that when prehospital 12 lead ECG was in its infancy
some of the same concerns were voiced by paramedics and physicians alike.
I feel a little guilty about my knee-jerk reaction because now that I know more
about the technology and what it can offer, I believe it can be of great value
to the paramedic, physician and patient.

(1) The first thing I learned is that
the prices have been plummeting over the last few years. The current price
of some new, low-end devices is around 4 to 8 thousand dollars. They can
top out at $70K for new, portable units that are really nice. Physiocontrol/Medtronic has announced
a project with Sonosite to incorporate sales of
ultrasound machines
with future cardiac monitor/defibrillators. Your future
heart monitor will probably have this technology built in. Are you going
to continue to refuse to use it when it is sitting right in front of you or will
you embrace the technology early?

(2) During my research I found that most ED physicians were
trained "on the job" in the FAST exam and in only 6 to 24 hours. Most of the
studies involving
paramedics used a 6 hour training session. As with any other skill, practice and repetition are the keys to competence. Some paramedics will pick it right up and be great at it. Some will be average and some will be weak at the skill. Paramedic resistance to the idea may be due to a fear of not being able to master this skill.

(3) Like any other technology, if we can prove to the insurers
that the patients can benefit, there may be reimbursement. It drives me
crazy to hear paramedics say, "where are the studies that support its use in the
field". You have to put it out there and use it in order to do the
studies. At this point there are dozens of studies all very supportive of
the idea. In fact, not a single study anywhere suggests that prehospital use had
problems or a "downside".

(4) The
portable machines I have looked at are very
easy to operate. Most devices have only a few controls and the "Knobology" can be easily taught
within the 6
hour class.

(5) Ultrasound has come a long way.
Back in
1980 my good friend Mary Beth, who was the head sonographer at
Deaconess Hospital in Buffalo, NY, she
showed me the state-of-the-art ultrasound machine she was using at the time. The US machine was as big as a refrigerator back then. She would show me images
that I could barely understand.
In the early 80s the images were hazy shadows that required a tremendous
anatomical and patho-anatomical knowledge to interpret. I was impressed by
her ability to read what basically looked like a snow storm on the screen.
This is not true today. The images are very clear and most paramedics can
immediately identify and understand the underlying anatomy and pathological
findings that would be needed in the field. This
study showed a 100%
agreement between paramedic ultrasound assessments and physician diagnosis.
The ultrasound can also be effectively performed in a moving ambulance (backed
by a study) and movement artifact is more
forgiving than ECG movement artifact. In my experience, this is the most
asked question by EMSers.

(6) I was astonished by the number and
depth of
prehospital uses. In addition to the obvious OB uses, there are as many medical indications as there are trauma
indications. My first endeavor into US was to learn
about pneumothorax identification. US can be used in
60 seconds to
immediately identify a likely pneumothorax. The negative predictive value
for pneumothorax using ultrasound is 100%. Pneumos that
are even too small to be detected by physical exam or chest x-ray can be easily
identified with US. This can
quickly be
done in a moving ambulance with very little issue of movement artifact. When we
breathe, the visceral lung pleura slides against the chest wall if it is intact. By
looking for the lung sliding sign in B-Mode or, at the click of a button, M-mode, a paramedic can
quickly identify a
potential collapsed lung
by discriminating between two specific images. The
"seashore sign" is the normal lung and the
"barcode sign" is the
potential pneumothorax. By marching the probe down the
chest, looking for "lung point", one can determine how big the collapse is. I am sure
paramedics can
quickly master this easy task. You can also use color power Doppler to look for lung sliding. This technique is called
"Power Slide". There
is no question in my mind that the E-FAST
would be very useful in EMS. Additional uses include identifying
early pregnancy, number of fetuses, fetal heart rate,
second trimester issues, delivery position and placental location, the ultrasound can also tell us about
cardiac capture during pacing,
normal
abdomen vs.
abdominal
bleeding, thoracic bleeding,
normal
vs. aortic aneurysm,
cardiac tamponade, cardiac strength,hydration/volume status,
psuedo-EMD vs. true EMD and occult Vf. Yes that's right,
in some rare instances Vf
exists while asystole is observed on the ECG. Ultrasonography has
correctly identified this and allowed for proper defibrillation. A quick
ultrasound of the neck
can identify if the ET tube is in the esophagus rather
than the trachea or allow us to clearly see the distension of the
IJ in heart
failure assessments (Remember you can't use the EJ for this! The IJ is
typically difficult to assess in the field). It takes a little more skill but
US guided IVs can be useful in large patients and patients with poor veins. More exotic
uses include differentiating CHF/Pulmonary Edema from exacerbated COPD by looking
at the number of B-lines in the lungs (see fig. above), detecting
pulmonary embolus and identifying
skull and
long bone
fractures. Ocular ultrasound is quick, easy and can detect retinal
detachment, papilledema and increased ICP by indirect methods. Graves
disease/Hyperthyroidism/thyroid storm has a sensitive and specific finding on ultrasound. There are even
high end units that can scan the middle cerebral artery to look for stroke or
midline shift indicating swelling. This
is by no means a complete list of techniques that could be used in EMS.

(7) All EMS trauma protocols to date indicate that the device will be used on
the way to the hospital in a moving ambulance. I believe this may actually shorten scene
time because medics will want to get into the ambulance to use this technology. Most authorities say that the average scan time both in the ED and field
averages 3 minutes. The ambulance can be moving while the ultrasound machine is
in use. For cardiac arrest, where transport is not the priority,
ultrasound units are small, battery operated, boot-up in seconds and can be
taken to the patient side for immediate detection of the H's and T's. You
can easily scan the heart and IVC without interrupting CPR or ventilations. If
you think you can accurately and reliably identify the H's and T's without the aid of
ultrasound in the arrested patient, you are deluding yourself.

(8) Like anything else, some physicians will love the idea, some will hate
it and some will be unsure. I recall many physicians
hating the idea of 12 lead machines in the ambulance. They would frown and
warn don't waste any time doing them. Back then we never dreamed of bypassing the ED and going directly to the cath lab but this has become commonplace in many cities. Today those same doctors would probably insist that you should
have done one at the scene and then several serial ECGs on the way in.

(9) As it turns out, physicians and
paramedics are
allowed to possess and operate ultrasound machines in every state. A very important point to remember is that our goal is not to become
certified ultrasonographers. We only need introductory training to look for a few
emergency conditions. This abbreviated style of use goes by many names:
limited exam, Point of Care
use (POC)
, focused examination, goal directed or goal oriented exams.
Basically a question is asked i.e. "does the patient have a cardiac
effusion?". The clinician would answer yes or no based on the exam. These
cursory exams would not take the place of the more formal comprehensive ultrasound study if
needed. Credentialing to use ultrasound can come from the hospital,
similar to how ED physicians are credentialed or even the EMS educational system
can do this. While at a WINFOCUS conference in South Carolina a few years ago, I heard a physician lecturer during his plenary presentation say "I object
to over regulation of this device! No one credentialed me to use my
stethoscope and no one credentialed me to use a 12 lead machine. Just as a nurse or
respiratory therapist uses a stethoscope in their own unique way to get answers,
I believe the ultrasound machine will be used in a very similar way with each
specialty." I absolutely agree with him in that we should not create
obstacles that will slow the propagation of this technology out to the patients.

(10) We have more than 50 years of experience with
clinical ultrasound. It
is true that ultrasound
is a form of non-ionizing radiation which can induce some free radicals in tissue, at
very high levels it can translocate genetic material. Most notably it can heat, mechanically vibrate and cavitate the
tissues. Scientists have known that when very high doses are given over a long
time period there are damaging biological effects on tissues. While this is true in the laboratory
it has not been observed in the human clinical setting. The technology has a long history of safety
and effectiveness. It may even reduce the need for CT and radiographs which
expose the patient to ionizing radiation. The
amount of US energy we would use in EMS is very small in comparison to a
standard full ultrasound study. Currently, there has
never been any conclusive link to injury, disease or any other problem with appropriate medical use and
supervision.

(11) It's time to come to grips with
the truth! Most of our physical exam tests have poor
sensitivity and
specificity even if they are done properly by experienced providers. Simply put
- physical exam and vital sign assessment doesn't work well enough to allow us to make accurate
decisions for our patients in a reliable way. Patients with life threatening bleeds can have
relatively normal vital signs until it's too late due to vasoconstriction.
A patient with a failing heart or severe cardiomyopathy can have perfectly
normal 12 Lead EKGs, normal vital signs or even hypertension but if you were to look at the heart you would
see a very different clinical picture. An abdomen full of blood can be soft,
non-tender with normal vital signs. EMS educators have brain washed you to
think that history and physical exam is very accurate. It's not their fault, they
were taught that as well. Physical exam is not
always accurate or reliable. Some estimates are that it is only 30% in emergency
scenarios. That's why docs use more technology to get
the answers. History, physical exams AND
imaging with ultrasound would give us the best chance at being accurate with our
clinical impressions and therefore more accurate with treatment and
triage.

(12) How will this change our care?
I see real value with looking for pneumothorax,
cardiac tamponade
and AAA.
I believe the E-FAST exam would definitely help trauma patients. Visualizing the
IVC volume
could be very
useful in guiding IV therapy. Looking at heart action in cases of shock
could guide more appropriate use of inotropes. Procedurally it can aid with
external pacing, help you start a difficult IV and even tell if a tube is in the
esophagus. The
real value of Paramedic US may be
similar to what we, as paramedics, do with the 12 lead ECG. The 12 lead does
not drastically change our field care but it sure does dramatically help the patient by
ramping up the response at the hospital. The positive ultrasound exam may do
the same thing by speeding the patient to the most appropriate location like
ED/CT/OR or
treatment such as having O- packed cells
hanging upon arrival. Only time will tell. I feel
with close physician medical control we may be able to help pioneer this technology
to better care for our patients. The paramedics and physicians we work with
are very clever people. I am sure good things can come from our
efforts. You have to try something to succeed at it!

Cross
section anatomy Spend some time looking at Plates
5.5,
5.7 and 6.8. The liver, spleen, and full urinary bladder are your "acoustic windows" into the
body. When you study these plates try to think about the anatomy in 3D and
tomographically.

Great US Intro by Dave Spear, MD. Dr.
Spear
is one of the pioneers of field US in the USA

Society of Ultrasound in Medical Education
Learning
Modules (these are very well done)

GE's Vscan -
Cool device but these are fairly
delicate devices. No live composite video out
connector is a problem. In addition to that the first generation (sector probe only) can't do superficial things like look at veins for IV
starts. Recently the second generation Vscan has corrected that by adding a dual transducer on the same probe! This does increase the utility of the device. See the new Vscan . If you are into hearts it does directional color flow, records cine loops and can measure Aorta / IVC.
It's nice for OB as well.

Contact me if you would like me to come out and present a
promotional PowerPoint and demo some devices at your location. There
is no charge for any location in NYS. I will present to any size group or audience.
EMS dinosaurs, hecklers and nonbelievers are not only welcome but encouraged to
come. I'll bet I can change their minds. Just invite me and put on the coffee. Some example PPT Slides (12.3 Megs) Contact:Peter@ParamedicUltrasound.com

Originally published to the web: 10/05/2010
Last update: 08/18/2016 21:00:00